Crank Pulley adapter or add on

[bbarnumboy]

does anyone know of any adapters or add on pulleys, to add another row onto the crankshaft pulley? I am looking to add a 6-8 rib on to the end of my M42 pulley for a Blower.

any ideas..I found this picture.

http://members.iinet.net.au/~u9013943/cars_files/blowerdrive2.jpg